1. Field of the Invention
This invention relates generally to a connection on a plastic tank, and more particularly to a sealed connection that is impervious to hydrocarbon permeability.
2. Description of the Prior Art
As acceptable levels of hydrocarbon emissions are lowered by governmental agencies, hydrocarbon permeation at welded connections to plastic tanks has been recognized as a principal source of such permeation in fuel tanks.
To eliminate permeation paths through the tank wall plastic that is impervious to hydrocarbon permeability is incorporated in the wall. Components welded to the outer surfaces of plastic fuel tanks require communication to the internal storage area of the fuel tank. The weld is located external to the tank and radially outside of the outer diameter of the cut hole. If a hole is cut in the tank wall to provide access to the tank's contents, the hole compromises the integrity of the plastic that is used to prevent hydrocarbon permeability.
A need exists in the industry to seal the discontinuity at the hole and to restore hydrocarbon impermeability without deviating substantially from current plastic fuel tank production methods including use of the access hole.